1. Technical Field
The present invention relates to a column packing material, a column using the same, and a method of separation using the same.
2. Related Art
8-Hydroxy-2′-deoxyguanosine (8-OHdG) has been known as an oxidative stress marker, and has widely been used as a marker indicating oxidative damage of DNA. When 2-deoxyguanosine, which is an intracellular DNA constituent, is exposed to oxidative stress, it reacts with a reactive oxygen species or free radical, and 8-OHdG as a reaction product is then released into body fluid, particularly into urine.
It has been known that elevation of the 8-OHdG level in body fluid is generally ascribable to extrinsic generation of reactive oxygen induced by environmental chemical substances, ultraviolet radiation, ionized radiation and so forth, and intrinsic generation of reactive oxygen ascribable to irregular life causative of cancer or lifestyle-related disease. As specific cases, elevation in 8-OHdG level has been reported in relation to colorectal cancer, lung cancer, childhood cancer, diabetes, chronic hepatitis, coronary artery disease, Alzheimer's disease, atopic dermatitis, smoking, and drinking. On the contrary, lowering in 8-OHdG level has been reported in relation to intake of vitamin E, vitamin C, β-carotin, curcumin, green tea, redwine, tomato source, and Brussels sprouts. Beside these, also investigations aimed at detection of DNA damage, in association with production of reactive oxygen induced by physical exercise, are in progress.
Methods of measuring 8-OHdG is exemplified by a method (HPLC-ECD method) using an electrochemical detector (ECD) coupled with high performance liquid chromatography (HPLC).
On the other hand, a technique of separating and concentrating 8-OHdG in samples, in advance of measurement of 8-OHdG by the HPLC-ECD method, is described in Japanese Laid-Open Patent Publication No. 2007-121271.
Further investigations by the present inventors into a technique of analyzing 8-OHdG in samples such as body fluid using a chromatographic method, however, revealed that some samples after the column chromatography peaks of 8-OHdG in the HPLC-ECD measurement, overlapped with peaks of other components.
It is therefore an object of the present invention to provide a technique capable of more readily and exactly separating 8-OHdG, contained in samples, from contaminants.